My own sentimental favorite, however, is "elastic", which -- so help me God -- means "hard, unbending and brittle" when you're taking about the crust of a planet. (Its opposite case in this situation is "viscous".)

It seems that the leading man-made cause of global warming is environmentalism; specifically, efforts to improve air quality by reducing pollution, New Scientist reports.

(Emphasis added.)

No it doesn't. You made that up/misread the article. The (New Scientist) article talks about warming in Europe, which is a pretty small part of the globe. It doesn't address global warming at all.

It's complex. Soot is dark, true, but if it heats up enough, and at high altitudes, it would re-radiate a certain amount of energy back into space. You can formulate two thought experiments. Suppose all the soot was formulated into a huge sheet 500 miles above the earth, and furthermore assume that there was a highly reflective layer of ice crystals far below it. This would almost certainly reduce surface temperatures. The soot would absorb light, and in the process heat up until the energy it re-radiates as black body radiation is equal to the absorbed energy. (Assume for the purposes of this thought experiment that it does not decompose or react.)

On the other hand, suppose the soot was formulated into a huge sheet at 1 meter above the surface. This would increase surface temperatures. The soot would still heat up and re-radiate, but since it so close to the surface, much of the heat will be conducted to the air and ground.

Another way to think about this is to imagine a greenhouse. If you throw a bunch of black stuff on top of the greeenhouse, on the outside, the greenhouse will cool. (Assuming that it does not provide any significant insulation.) On the other hand, if you put the black stuff inside the greenhouse, it will warm the greenhouse.

In reality, we don't have a simple structure like the glass in the greenhouse. We have this very complex, dynamic structure known as the atmosphere, and the soot is flowing around inside of it in different layers, etc. So, the soot interactions are much more complex and dynamic. That's why there are different possible effects due to soot.

Um, are you sure about that? What about nuclear winter? Scientists claimed the soot from burning cities of a global nuclear war would drive temperatures so low that crops would fail, and whoever didn't die from radiation would starve to death.

Ash clouds would block radiation from reaching the ground, but black particles would not reflect it back into space either, so the heat would just be trapped in the upper levels of the atmosphere.

I find the way politics aligns with risk to be interesting

That's my point exactly. Back when the fear was global cooling, science (supposedly) proved that soot would worsen the problem by cooling the earth even more. Now that the fear is global warming, science (supposedly) proves that soot worsens the problem by warming the earth even more.

I can't be the only person who smells a rat. These people have long used science solely as a means to push their political agenda, but when President Bush draws scientific conclusions in the opposite direction, these same people go plum crazy. OK, children, can anybody spell:
h-y-p-o-c-r-i-s-y?

I find the way politics aligns with risk to be interesting. For example, why is it that the left seems to be more concerned about the danger from global warming and chemicals, while the right is more concerned about the danger of terrorism? How much of this is due to real differences in the way that liberals and conservatives think, and how much of this is due to history and group identification?

And then there's soot from fires -- which of course is black, absorbs visible light like crazy and re-emits it as IR, and is a definite greenhouse increaser.

Um, are you sure about that? What about nuclear winter? Scientists claimed the soot from burning cities of a global nuclear war would drive temperatures so low that crops would fail, and whoever didn't die from radiation would starve to death. Personally, I think Steve Plunk has got it right.

Is the Web headline misrepresenting the article itself?

No, I think the problem is that you tried to comment authoritatively on a technical issue in an area outside of your expertise.

Please don't let this deter you, however, from further posts on environmental science--they are always good for a chuckle.

Aerosol particles are an entirely different matter, and whether they increase or decrease global warming depends on what their albedo at different wavelengths is (e.g., whether they're light or dark in color in visible light -- and in the infrared). Sulfate mists -- such as those given off by volcanoes, and by some forms of smog -- are anti-greenhouse and so cool the planet; they're light-colored and reflect incoming sunlight back into space, but they're transparent to IR coming up from below and so let it escape back into space. This is actually officially called the "anti-greenhouse effect". (It's now generally believed that the above-average volcanic activity in the third quarter of the 20th century explains the temporary slack-off of global temperature rise in that period.)

Cumulus clouds -- made out of liquid water droplets -- also have an anti-greenhouse effect, but a tremendously weaker one. Cirrus clouds -- made of solid water ice crystals -- have the opposite effect: water ice is translucent in visible wavelenghts but actually dark-colored in the infrared, so cirrus clouds warm up the planet. (The possible changes in the balance of cirrus to cumulus clouds on Earth as a whole is one of the chief remaining uncertainties in the climate debate, and just about the only possible mechanism GW skeptics can come up with as to why our CO2 increase might conceivably NOT warm up the planet -- if we're very, very lucky).

And then there's soot from fires -- which of course is black, absorbs visible light like crazy and re-emits it as IR, and is a definite greenhouse increaser. That's one case in which economic development of the Third World unquestionably would also take a chunk out of GW. Unfortunately, the additional amount of CO2 pumped into the air by a developing Third World -- unless and until we can come up with technological countermeasures -- will vastly outweigh the anti-GW benefits from its getting rid of primitive cookfires and industrial forges. Which is why we need to get cracking on the development of those countermeasures.

And in that category, there actually is one rather wild idea floating right now that it might be worthwhile to deliberately dump large amounts of sulfate mists into the air -- IF we can't find any better countermeasure. In fact, the proposer is Paul Crutzen, winner of the Nobel Prize in Physics for his unravelling of the precise nature of man-made ozone destruction. "A few years ago I would have said, 'I'm not touching that.' " Now he's getting so desperate about the apparent lack of willingness of humanity to develop any other countermeasures that he's talking about this one. See the Oct. 20, 2006 "Science, pg. 401 (again not available for free on the Web, dammit) and his article in the August 2006 "Climatic Change".

That's not to say that a more detailed, quantitative analysis of record high temperatures would be meaningless. Just that that mere qualitative fact alone is not enough to disprove warming in Sacramento.

Additionally, CFCs are not themselves aerosols, since they are gases (at atmospheric pressures), not particulates.